From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7266C432C0 for ; Mon, 25 Nov 2019 17:41:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93C2220835 for ; Mon, 25 Nov 2019 17:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574703666; bh=B705o2O9nueunH95SS6+Tbmc79pENOFph/Yp7UTp9y4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ddNyXGWLnd9JjdUpE25OIn5nl5OTOasSVl154r88uYFTkngJJspxOtqv88CTMYiVm FZKkaB9CDtBIHYFkWqcr26di4DYHI+Vd+oPpx+nCDiYOXT5UrtPDxZ/0pFgw6gl24q KaZQjoOyY4tS/DBIDsYR4ZkziV01RYifKWGxVgkA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725868AbfKYRlG (ORCPT ); Mon, 25 Nov 2019 12:41:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:46486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725851AbfKYRlF (ORCPT ); Mon, 25 Nov 2019 12:41:05 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EABD220835; Mon, 25 Nov 2019 17:41:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574703665; bh=B705o2O9nueunH95SS6+Tbmc79pENOFph/Yp7UTp9y4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TWTF+Rc+1QNj+TF6e/5EYlY7s0rlyPDkdx4+xTwy4rSH5Gosc9wnFMPC4uB2GFsoF sa/xH7rmhOqe4W08IGtv2kPul9qzxZ8+fHGCYwuDzU2QxYhfU3dPwa2sy6BwS6kzfh DjkHt5SNlI7l5ebsHd2pA7udDQPhx3QeBBoIIZVY= Date: Mon, 25 Nov 2019 18:41:03 +0100 From: Greg KH To: Lee Jones Cc: Sasha Levin , stable@vger.kernel.org Subject: Re: [PATCH 4.9 3/8] arm64: fix for bad_mode() handler to always result in panic Message-ID: <20191125174103.GA2872072@kroah.com> References: <20191122105253.11375-1-lee.jones@linaro.org> <20191122105253.11375-3-lee.jones@linaro.org> <20191125134700.GA5861@sasha-vm> <20191125144429.GF3296@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191125144429.GF3296@dell> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Nov 25, 2019 at 02:44:29PM +0000, Lee Jones wrote: > On Mon, 25 Nov 2019, Sasha Levin wrote: > > > On Fri, Nov 22, 2019 at 10:52:48AM +0000, Lee Jones wrote: > > > From: Hari Vyas > > > > > > [ Upstream commit e4ba15debcfd27f60d43da940a58108783bff2a6 ] > > > > > > The bad_mode() handler is called if we encounter an uunknown exception, > > > with the expectation that the subsequent call to panic() will halt the > > > system. Unfortunately, if the exception calling bad_mode() is taken from > > > EL0, then the call to die() can end up killing the current user task and > > > calling schedule() instead of falling through to panic(). > > > > > > Remove the die() call altogether, since we really want to bring down the > > > machine in this "impossible" case. > > > > Should this be in newer LTS kernels too? I don't see it in 4.14. We > > can't take anything into older kernels if it's not in newer ones - we > > don't want to break users who update their kernels. > > Only; 3.18, 4.4, 4.9 and 5.3 were studied. > > I can look at others if it helps. You have to look at others, we can't have regressions if people move from one LTS to a newer one. thanks, greg k-h